Using Arrays

Artikkeli
06/05/2016

An array is a data structure that contains several variables of the same type. The variables are treated as a single collection. Although you can already create arrays in C/AL, you can now use arrays from the .NET Framework. Choosing whether to use a C/AL array or a .NET Framework array depends on how you intend to use the data.

For this scenario	Use this array type
Your C/AL code uses .NET Framework interoperability extensively, and you must share the array among many methods.	.NET Framework array
Your C/AL code mostly uses basic C/AL types and does not interoperate with the .NET Framework.	C/AL array

To use a .NET Framework array in C/AL, you must use the System.Array class in the .NET Framework class library, which is the class from which all arrays inherit. When interfacing with an array in C/AL, you must use the following methods of the System.Array class to create and access elements in the array.

Method	Description
CreateInstance	Creates a new array instance that is passed to a method or property.
SetValue	Sets a value in an array element.
GetValue	Gets a value from an array element

Many .NET Framework classes implement these methods. Therefore, they are available for you to use in C/AL code. If you are writing your own .NET Framework code and want to use it in Dynamics NAV, then you must implement these methods yourself.

In C/AL, some .NET Framework data types, such as strings, integers, and decimals, are automatically converted to C/AL types. If a .NET Framework array contains these data types, then you create an assembly that contains methods that return the information about the data types and then reference the assembly in the C/AL code. This concept is illustrated in the following examples.

Example: Using Native C/AL Data Types in a .NET Framework Array

The following example shows how you can use a .NET Framework array for an integer data type.

In Visual Studio, create a C# class library project called NavInteropHelper that contains a method that returns the information about the integer type as follows:


namespace Microsoft.Dynamics.Nav.NavInteropHelper;  
{  
    public class WrapInt32  
    {  
        public static Type GetTypeOfInt32()  
        {  
            return typeof(Int32);  
        }  
    }  
}

Build the project, and then copy the assembly to the Add-ins folder of the Microsoft Dynamics NAV Windows client installation folder. By default, the path of the installation folder is C:\Program Files\Microsoft Dynamics NAV\110\RoleTailored Client or C:\Program Files (x86)\Microsoft Dynamics NAV\100\RoleTailored Client.

In the development environment, open a Dynamics NAV object, open the C/AL code, and then create the following C/AL variables.

Variable name	DataType	SubType
varDotNet	DotNet	'NavInteropHelper, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.Microsoft.Dynamics.Nav.NavInteropHelper.WrapInt32
varArray	DotNet	'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Array
arraySize	Integer
i	Integer
alData	Integer

On a trigger of the Dynamics NAV object, add the following C/AL code to create, fill, and implement the array.

// Sets the number of elements in the .NET Framework array.  
arraySize := 10;  

// Creates an instance of the .NET Framework array that contains the Int32 type.  
varArray := varArray.CreateInstance(varDotNet.GetTypeOfInt32(), arraySize);  

// Clears the object instance because it is no longer used.  
clear(varDotNet);  

// Sets the data in the array.  
FOR i := 0 TO (arraySize -1) DO  
  varArray.SetValue(i+100,i);  

// Gets the array data and validates the content. The object that is returned by  
// GetValue is automatically converted into a C/AL integer in the assignment.  
FOR i := 0 TO (arraySize -1) DO  
BEGIN  
  alData := varArray.GetValue(i);  
  if alData <> (i+100) then  
    error('Invalid array data in element %1, expected %2, actual %3', i, i+100, alData);  
END;

Example: Using User-Defined Classes in a .NET Framework Array

This example shows how you can use a .NET Framework array that includes user-defined classes.

In Visual Studio, create a C# class library project called NavInteropHelper that contains methods that return the information about the types as follows.


namespace Microsoft.Dynamics.Nav.NavInteropHelper;  
{  
    public class WrapInt32  
    {  
        public int Data { get; set; }  
        public WrapInt32(Int32 value)  
        {  
            Data = value;  
        }  
    }  
}

Build the project, and then copy the assembly to the Add-ins folder of the Microsoft Dynamics NAV Windows client installation folder. By default, the path of the installation folder is C:\Program Files\Microsoft Dynamics NAV\110 RoleTailored Client or C:\Program Files (x86)\Microsoft Dynamics NAV\100 RoleTailored Client.

In the development environment, open a Dynamics NAV object, open the C/AL code, and then create the following C/AL variables.

Variable name	DataType	SubType
varDotNet	DotNet	'NavInteropHelper, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.Microsoft.Dynamics.Nav.NavInteropHelper.WrapInt32
varArray	DotNet	'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Array
arraySize	Integer
i	Integer
alData	Integer

On a trigger of the Dynamics NAV object, add the following C/AL code to create, fill, and implement the array.

// Sets the number of elements in the .NET Framework array.  
arraySize := 10;  

// Creates an instance of the .NET Framework object so the type information can be retrieved.  
varDotNet := varDotNet.WrapInt32(1);  

// Creates an instance of the .NET Framework array that contains the user-defined type.  
varArray := varArray.CreateInstance(varDotNet.GetType(), arraySize);  

// Clears the object instance because it is no longer used.  
clear(varDotNet);  

// Sets data in the array.  
FOR i := 0 TO (arraySize -1) DO  
BEGIN  
  varDotNet := varDotNet.WrapInt32(i+100);  
  varArray.SetValue(varDotNet,i);  
END;  

// Gets array data and validates content.  
FOR i := 0 TO (arraySize -1) DO  
BEGIN  
  varDotNet := varArray.GetValue(i);  
 // Gets the integer value from the .NET Framework object using the Data property.   
  alData := varDotNEt.Data;  
  if alData <> (i+100) then  
    error('Invalid array data in element %1, expected %2, actual %3', i, i+100, alData);  
END;

Jaa

Using Arrays

Example: Using Native C/AL Data Types in a .NET Framework Array

Example: Using User-Defined Classes in a .NET Framework Array

See Also

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